Pneumatic vehicle tire having a breaker arrangement surrounded at least in its edge regions by at least one cover ply and method of making the same

ABSTRACT

A pneumatic vehicle tire comprises a single ply or multi-ply radial carcass anchored to beads, a tread, and a breaker arrangement provided between the carcass and the tread. The breaker arrangement is preferably built up of at least two cut breaker plies with the threads or cords of the cut breaker plies, which serve as strength carriers and extend parallel to one another in the respective ply, crossing at a predetermined angle to the central mid-circumferential plane. The tire also comprises at least one cover ply of cords or threads extending substantially in the circumferential direction of the tire, at least one cover ply surrounding the breaker arrangement at least in the breaker arrangement&#39;s edge regions. In the preferred embodiment the breaker arrangement (4) has threads or cords (9) of non-metallic material and a material with a low thermal shrinkage or no thermal shrinkage is used as the material for the treads or cords (8) of the at least one cover ply (5).

The invention relates to a pneumatic vehicle tire comprising a singleply or multi-ply radial carcass anchored to beads, a tread, a breakerarrangement provided between the carcass and the tread, the breakerarrangement preferably being built up of at least two cut breaker plieswith the threads or cords of the breaker plies, which serve as strengthcarriers and extend parallel to one another in the respective ply,crossing at a predetermined angle to the mid-circumferential plane andalso comprising at least one cover ply of cords or threads extendingsubstantially in the circumferential direction of the tire, the at leastone cover ply surrounding the breaker arrangement at least in thebreaker arrangement's edge regions.

BACKGROUND OF THE INVENTION

Whereas the radial carcass forms the support construction of the tireand gives strength to the tire, the breaker arrangement, providedbetween the carcass and the tread, consists of at least two cut breakerplies, and serves to give the pneumatic vehicle tire the desired drivingcharacteristics, in particular the necessary stability. In order toprevent separation of the breaker arrangement, in particular, at highspeeds, this separation predominantly occurring in the edge regions ofthe breaker plies, the breaker arrangement is, at least in this region,covered over with a cover or bandage layer having threads or cords whichextend substantially in the circumferential direction of the tire.

Pneumatic vehicle tires of the named kind are customarily manufacturedusing a cylindrical drum by laying the individual tire components, suchas the carcass and sidewalls, one after the other onto the drum. Afterthe beads have been set in place and the carcass turned over aroundthem, the tire blank is then shaped to a toroid, the breaker pliesapplied to the tread and then the assembly is placed in a tire mold inwhich the tire profile is formed and the tire is vulcanized.

In order to finally shape the tire blank into the tire mold, theindividual components of the tire must be extensible in order to allowthe final stretch of the tire into the tire mold.

On the other hand, an extension of the tire under static or dynamicloading should be avoided as far as possible in the finished tire. Whilethe breaker plies permit an extension to the requisite degree as aresult of their cords which are arranged in a crossed arrangement at apredetermined angle to the mid-circumferential plane, this can only beachieved for the cover or bandage ply, with its cords which extendsubstantially in the circumferential direction of the tire, through asuitable choice of the cord material. However, in this respect, accountshould additionally be taken of the fact that the cover or bandage plyserves to prevent a separation of the breaker arrangement. Despite theextensibility required for the formation of the tire, the cover orbandage ply must therefore have adequate strength.

Nowadays, breaker plies customarily contain steel cords as reinforcingelements, whereas the cover ply comprises nylon cords. However, the useof steel cords in the breaker arrangement is disadvantageous due to theincreasing endeavor to reduce tire weight.

SUMMARY OF THE INVENTION

The invention is thus based on the object of further development of apneumatic vehicle tire of the initially named kind so that its weight isreduced as much as possible without impairing the requiredcharacteristics of the pneumatic vehicle tire.

This object is satisfied in that the threads or cords of the breakerarrangement are threads or cords of non-metallic material; in that amaterial with low thermal shrinkage or no thermal shrinkage is used asthe material for the threads or cords of the cover ply; and in thatextension of the tire is ensured into the tire mold during itsmanufacture, through the choice of the material of the threads or cordsof the cover ply alone, or in conjunction with the nature of thebuild-up and/or of the application of the cover ply and/or through thenature of the build-up of the threads or cords of the cover ply, butadditional extension of the tire is prevented.

As a result of the use of non-metallic reinforcing elements instead ofsteel in the breaker arrangement, the tire weight is advantageouslyreduced. In order to nevertheless give the tire the desired properties,the cover ply is formed in the given manner.

The choice is thus made so that the extension of the green tirenecessary for molding the green tire into the tire mold is possible; sothat no shrinkage of the tire occurs on heating up of the completed tireafter vulcanization, or during use; and so that extension of the tireunder static load (air pressure) or dynamic load (centrifugal force) iscounteracted with a force which is as large as possible in order toprevent an undesired growth of the tire.

In contrast to a pure steel radial tire, there is the problem, whennon-metallic reinforcing elements are used in the breaker arrangement,that the breaker material has no or only a small bulk modulus. Ashrinkage of the cover ply as a result of warming would therefore leadto a deformation of the tire and thus to a worsening of the tireproperties leading up to its destruction.

In accordance with the invention, a material for the threads of cords ofthe cover ply is preferred which has a modulus of elasticity which is aslarge as possible, at least in the initial range of tire extension, butwhich still just permits an extension of the tire into the mold duringmanufacture. An undesired extension of the tire during use is therebysubstantially prevented.

Rayon has proved to be a particularly suitable material for the threadsor cords of the cover plies. Rayon has a comparably high initialmodulus, particularly in comparison to nylon, i.e. a relatively steepgradient of the stress-strain curve (force-extension curve) which islarge enough to counteract an undesired extension of the tire but whichpermits an extension of the tire into the tire mold. Moreover, rayon ispractically free of thermal shrinkage.

Polyester may also be used for the threads or cords of the cover plyproviding that its modulus of elasticity is sufficiently large and itsthermal shrinkage sufficiently small. High-modulus-low-shrinkagepolyesters (HMLS) of this kind are already tested.

Furthermore, threads or cords of aramid, or of a hybrid material witharamid, have proved to be advantageous for the cover ply. Aramid and thenamed hybrid materials are characterized by a particularly high tensilestrength and thus prevent undesired tire growth under static or dynamicloading. In this way, the tire of the invention has particularly goodfast running characteristics.

The extension of the tire necessary for the forming of the tire tread orprofile can be set via the build-up of the cover ply, in particular, viathe titer, i.e. the weight related to a specific length, of the threadsor cords and their density in the respective ply, via the degree oftwist of the cords and via the type of winding of the cover ply. Thus,the extensibility of the tire increases by reducing thread density andreducing titer. In the same way, the extensibility of the cords can beincreased by a higher twist. Finally, the winding density and tension ofthe cover ply also codetermine the extensibility of the tire.

It has surprisingly turned out that when using these measures, even whenusing high modulus materials, in particular aramid materials, noproblems arise during forming of the tire profile.

In any case, the threads or cords of the cover ply are preferablyselected to be as thin as possible and as thick as necessary. The weightof the cover ply and thus the tire weight can be reduced in this way.

In a further embodiment of the invention, the breaker arrangementcontains cords or threads of textile material, in particular of aramid.Aramid has a particularly high strength combined with a low weight. Incomparison to steel, the weight can be significantly reduced.Particularly good tire properties are achieved by the combination of anaramid breaker and a rayon cover ply. In place of aramid, glass fibersor carbon fibers can also be used in the breaker arrangement.

In place of aramid, rayon or HMLS polyester can be used for thereinforcement elements of the breaker arrangement. Good tire propertiesalso result from this approach.

In accordance with a further embodiment of the invention, thegeometrical arrangement of the cover ply and/or the thread or corddensity in the cover ply are used in addition to the selection of thecord or thread material of the cover ply for achieving the desiredextension behavior of the tire.

For example, the cover ply can be provided only in the edge regions ofthe breaker arrangement where the danger of separation of the breakerarrangement is the highest. Through this arrangement of the cover ply,the extension of the tire into the tire mold in the central axial regionis practically unimpaired by the cover ply.

With a cover ply which surrounds the breaker arrangement over its entirewidth, the threads or cords of the cover ply in the shoulder region ofthe tire can consist of a material which is essentially non-extensible.In the middle tire region disposed between the two shoulder regions thethreads or cords of the cover ply can consist of a material whichpermits an extension of the tire by a predetermined amount under theconditions which prevail during tire manufacture, but substantiallyprevents extension of the tire.

Through this differential choice of material for the threads or cords ofthe cover ply in the shoulder regions, on the one hand, and in thecentral tire region, on the other hand, the extension of the tire whichis necessary for the arching of the tire blank and for the formation ofthe tire is made possible and the shoulder regions which areparticularly endangered by separation effects are strengthened. The useof an essentially inextensible cord material in the shoulder regions ispossible because the tire extension which is required here is very low.In the central tire region where a considerable tire extension isnecessary a larger extension is made possible by a suitable choice ofmaterial. Through adjustment of the permissible extension to the degreerequired during tire manufacture an extension of the finished tirebeyond this dimension can be largely prevented.

Aramid has turned out to be a particularly suitable material for thethreads and cords in the shoulder region of the cover ply and rayon forthe threads or cords of the cover ply in the central region of the tire.Whereas aramid has only a very low extensibility, rayon permits anextension up to a certain degree but generates a large restraining forcefor an extension which goes beyond this. The finished tire therebybecomes particularly stable.

The cover ply can be formed in the shoulder regions of the tire and/orin the central region of the tire by a helically wound strip bandage, aso-called jointless band (JLB). The cover ply in the central region ofthe tire can also be formed as a broad band in accordance with oneembodiment of the invention.

The sections of the cover ply in the shoulder regions and in the centraltire region can be respectively arranged either abutting one another oroverlapping one another. When using a strip bandage for both of the twoshoulder regions and also for the central tire region, the single stripsof different material can also be directly wound adjoining one anotheraround the tire, that is to say the start of the strip which is woundaround the center of the tire is set at the end of the strip woundaround the one shoulder region and the start of the strip wound aroundthe second shoulder region is set at the end of the strip wound aroundthe center of the tire. In this manner, a particularly uniform cover plyis obtained and the tire characteristics are improved.

The permissible extension of the cover ply during the manufacture of thetire can be restricted by choice of the cord material in the shoulderregions to a maximum of about 0.1 to 0.5%, in particular to about 0.3%,whereas in the central region of the tire a permissible extension duringmanufacture, for example in the range of between 2 to 3%, in particular2.5 to 2.7%, can be set through the choice of the cord material. Withthis choice, particularly good tire characteristics can be obtained.

These extension relationships can be particularly advantageously setthrough the combination of aramid in the shoulder regions of the tire,and rayon in the central tire region as materials for the cords of thecover ply. The stress-strain (force-extension) curves of aramid andrayon have a favorable relationship relative to each other for thispurpose. That is to say, substantially the same sized forces arerequired in the shoulder region and in the central region of the tirefor the extension of the breaker with the cover ply during the moldingof the tire with this choice of material, whereby a uniform molding andharmonious tire characteristics are achieved.

Aramid is preferably used as a material for the threads or cords of thebreaker arrangement with this layout of the invention. In this way, thetire weight is kept low. In conjunction with rayon for the threads orcords of the cover ply in the central region of the tire and aramid inthe two shoulder regions of the tire, one obtains a particularlyadvantageous tire assembly with high strength and low weight. Throughthe use of rayon which has no thermal shrinkage it is ensured thatduring heating of the tire no deformations arise as a result of thesmall bulk modulus of textile cut breaker plies. The combination ofaramid in the shoulder regions and rayon in the central region of thetire could, however, basically also be used with steel breakers. Thetire weight would however then be higher.

The extension behavior of the cover ply, i.e. the modulus of elasticityof the cover ply as a whole, can be directly influenced by the thread orcord density. A high cord or thread density produces a high modulus ofelasticity and, correspondingly, a small modulus of elasticity of thecover ply is produced by a small thread or cord density.

A further possibility for influencing the extension behavior of thecover ply through its construction is to alter the winding densityand/or the winding tension in order to adjust the extension behavior ofthe cover ply, i.e. its modulus of elasticity, in a deliberate manner. Alarge modulus of elasticity of the cover ply can thus be set by a highwinding density and/or by a high winding tension whereas,correspondingly, a small modulus of elasticity can be set by a smallwinding density and/or winding tension.

In accordance with a further embodiment of the invention, the windingdensity and/or winding tension are selected differently across the widthof the tire, with them being preferably selected to be respectivelyhigher or larger in the edge regions of the breaker arrangement. Thisallows the desired extension behavior, and, in general, the desiredproperties of the tire to be taken into account particularly well.

As already described, a high modulus of elasticity is necessary in theedge regions of the breaker plies, which correspond to the shoulderregions of the tire, in order to counteract the particularly largedanger of separation of the breaker plies here, whereas in the centralaxial region of the tire a smaller modulus of elasticity of the coverply is sufficient.

In accordance with a further embodiment of the invention, the setting ofthe desired extension properties of the cover ply can be achieved viathe build-up of the cords or threads of the cover ply by a correspondingselection of the degree of twist of these threads or cords. The cords orthreads are given an additional elasticity by increasing their degree oftwist in the cover ply thus leading to a reduction of the modulus ofelasticity of the cover ply. On the other hand, a larger modulus ofelasticity can be produced by a reduced degree of twist.

In order to set the desired extension behavior further, other measureshave proved to be particularly suitable. Thus, the cover ply can coverover the entire breaker ply or only a part of it, in particular the twoedge regions of the breaker plies. In the first case in particular, thecover ply can also be constructed as a singly-folded twin-ply.

In a cover ply made of helically wound strips, a so-called JLB(jointless band), the individual strip windings can overlap one anotherand the width of overlap can be selected to be different over the widthof the tire. In this manner, the extension properties can also be variedin a controlled manner over the width of the tire. In particular, alarge modulus of elasticity of the cover ply can be provided in theshoulder regions of the tire, whereas a small modulus of elasticity canbe provided in the central axial region of the tire. This can, forexample, be achieved by providing an overlap of the strip windings onlyin the regions which cover over the two edge regions of the breakerarrangement, or by making this overlap particularly large here.

The winding sense and winding direction of the strip bandage can, inaccordance with the further embodiments of the invention, also bedifferent over the width of the tire. In particular, the winding senseand winding direction on one side of the mid-circumferential plane canbe opposite to that on the other side (of the mid-circumferential plane.This also allows the tire properties to be influenced in a controlledmanner.

In summary, the modulus of elasticity of the cover ply can be adjustedin a controlled manner by using the various measures described above,that is to say, the stress-strain (force-extension) curve of the coverply can be given a desired characteristic.

Moreover, the breaker arrangement can also be designed in differentways. In particular, one or more of the breaker plies can have amulti-part construction, for instance with a gap in the central axialregion. The type and construction of the reinforcing elements of thebreaker arrangement can also be used to influence the extensionproperties of the tire in a similar manner as for the cover ply.

Furthermore, the breaker arrangement can consist, in accordance with theinvention, either exclusively of non-metallic breaker plies or canconsist of both non-metallic and steel breaker plies (so-called hybridconstruction). In both cases, the cover ply design in accordance withthe invention has a favorable effect on the tire properties.

In accordance with a further layout of the invention, cords or threadsof the same material and with the same titer are used in the breakerplies and in the cover ply. Through this layout, the stocking ofmaterials is made easier and more cost-favorable since only oneparticular cord need be kept available for each type of tire.

Cords consisting of two twisted aramid threads with a titer ofrespectively 1670 dtex., i.e. grams per 10,000 meters, and also a corddensity in the breaker plies of about 70 to 120 cords per 10 centimetersand in the cover ply of about 60 to 90 cords per 10 centimeters haveproved to be particularly suitable, with the breaker arrangementpreferably being built-up of two aramid breaker plies and one aramidstrip bandage serving as the cover ply.

In accordance with a further embodiment of the invention, the corddensity in the breaker plies and in the strips of the cover ply are ofthe same size. This layout has the advantage that the breaker plies andthe strips for the cover ply can be manufactured from a singlerubberized ply. A rubberized ply can thus also be manufactured with thedesired cords at the required cord density in the form of an endlessband from which then both the breaker plies and also the strips for thecover ply can be cut off. In this way, the manufacturing of the tire ofthe invention is simplified.

A particularly favorable method for the manufacturing of such apneumatic vehicle tire lies in first manufacturing a rubberized ply withtextile cords at the required cord density and in that the stripsrequired for the cover ply are cut-away from this ply at the sidemargins, whereas the remaining part of the rubberized ply is used forthe breaker plies. In this way, a rubberized ply can be manufactured asa continuous band from which then both the strips for the cover ply andalso the breaker plies can be cut off. The manufacture is thereby madeparticularly simple and practically no cutting losses arise.

BRIEF DESCRIPTION OF THE FIGURES

Embodiments of the invention are shown in the figures and are describedin the following.

They show:

in FIG. 1, a cross-section through a pneumatic vehicle tire inaccordance with the invention;

in FIG. 2, a perspective partial view of a sectioned tire in accordancewith the invention;

in FIGS. 3 to 34, various variants of the cover ply in accordance withthe invention shown schematically;

in FIGS. 5b and 6b, the direction of strip bandage windings in FIGS. 5and 6, respectively;

in FIG. 35, a strain or extension diagram of tires with textile breakerplies and with various cover plies in comparison;

in FIG. 36, a perspective illustration of a rubberized ply for use inthe tire in accordance with FIG. 1;

in FIG. 37, a schematic illustration of a first variant of a breaker andcover ply arrangement in accordance with the invention to a scalereduced relative to FIG. 1; and

in FIG. 38, a further variant of a breaker and cover ply arrangement inaccordance with the invention in an illustration corresponding to FIG.37.

DETAILED DESCRIPTION OF THE INVENTION

The tire shown in FIG. 1 has a radial carcass 2 anchored to the beads 1,a tread 3 and a breaker arrangement 4 comprising two breaker pliespositioned between the carcass 2 and the tread 3, as well as at leastone cover ply 5 surrounding the breaker arrangement. The beads 1 areeach provided with a bead core 6 on which a bead filler or bead apex 7is arranged.

It can be seen from FIG. 2 that both the breaker plies of the breakerarrangement 4 and also the at least one cover ply 5 comprise mutuallyparallel cords or threads 8 and 9 respectively in the respective ply.Whereas the cords or threads 8 of the at least one cover ply 5 extendsubstantially in the circumferential direction of the tire, the cords orthreads 9 of the two breaker plies 4 of the breaker arrangement crosseach other at a particular angle relative to the central circumferentialplane of the tire.

FIGS. 3 and 4 show the arrangement of the cover ply 5 radially outsidethe breaker arrangement 4. In FIG. 3 the cover ply 5 surrounds thebreaker arrangement 4 over its entire width, whereas in FIG. 4 only theedge regions of the breaker arrangement 4 are surrounded by the coverply 5 which is now a two-piece cover ply.

In FIGS. 5 and 6, the cover ply 5 is, in contrast to FIGS. 3 and 4,formed as a helically wound strip bandage (JLB), with the winding of thestrip bandage 13 taking place from left to right in FIG. 5 and fromright to left in FIG. 6 as is indicated in FIGS. 5b and 6b by thebandage piece 10 and by the arrows 11 and 12 respectively.

In FIGS. 7 and 8 an embodiment is shown in which the individual windingsof the strip bandage 13 overlap, with the winding directioncorresponding on the one hand to that of FIG. 5 and on the other hand tothat of FIG. 6.

In FIGS. 9 and 10, the winding direction on the left and the right ofthe central circumferential plane 14 is in each case different.Otherwise, these embodiments correspond to those of FIGS. 7 and 8.

In FIGS. 11 to 16, the overlap between the individual windings of thestrip bandage 13 is different over the width of the tire. In FIGS. 11 to14 an overlap only occurs in the edge regions of the breaker arrangement4 and the strip bandage 13 is wound in the central axial region inabutting form or with gaps. In contrast, in FIGS. 15 and 16 an overlapoccurs over the entire width of the tire, this overlap being larger inthe edge regions of the breaker arrangement 4 than in the central axialregion of the tire. The winding direction is in each case different asis indicated with the arrows 11 and 12, respectively.

In FIGS. 17 to 28, the cover ply 5 is only provided in the edge regionsof the breaker arrangement 4. In FIGS. 17 to 20 each of the individualturns overlap and the winding direction is that indicated by the arrows11 and 12. In contrast, in FIGS. 21 to 24, the individual turns of thestrip bandage do not overlap. The winding direction is also shown hereby the arrows 11 and 12. FIGS. 25 to 28 correspond as regards theoverlap and the winding direction to FIGS. 17 to 20, but in comparisonto these figures have an opposite winding sense.

In FIGS. 29 to 32, the cover ply 5 is formed as a twin ply and is foldedonce either in the left or in the right edge region of the breakerarrangement 4. Although in FIGS. 29 and 30 the cover ply 5 is formed asa broad band, the cover ply 5 shown in FIGS. 31 and 32 is formed as ahelically wound strip bandage 13.

FIGS. 33 and 34 show a cover ply 5 which in each case covers over abreaker arrangement 4 with differently formed breaker plies. In FIG. 33the radially outer breaker ply is formed in two parts with a gap lyingin the central axial region of the tire. In contrast, in FIG. 34, it isthe radially inner breaker ply which is formed in two parts and has sucha gap.

The diagram of FIG. 35 shows the effect which can be achieved with acover ply 5 in accordance with the invention. The change of the tirediameter of a pneumatic vehicle tire with textile breaker plies is shownand indeed, firstly, for a tire in accordance with the invention with astrip bandage with rayon cords (curve I) and secondly for a tire with astrip bandage of nylon cords (curve II). The tire diameter is shown atvarious stages of the tire manufacture as well as for the completed tireat room temperature and when pumped up. The tire diameter is given hereas a percentage of the diameter of the green tire.

One can see that with a tire in accordance with the invention with arayon cover ply (curve I) the tire diameter remains almost unchangedthroughout tire production. On pumping the tire up, its circumferenceincreases by a small amount.

For a tire with a nylon cover ply (curve II) the tire diameter reducesby a considerably amount during vulcanization due to the thermalshrinkage of the nylon. The tire first reaches approximately thediameter of the tire with a rayon cover ply when pumped up.

The strip bandage 13 can be cut off from a rubberized ply 15 from whichthe cut breaker plies of the breaker arrangement 4 are alsomanufactured. A rubberized ply 15 of this kind is shown in FIG. 36. Therubberized ply 15 has cords 16 which extend parallel to one another andwhich are formed in the illustrated example of two or three threads 17which are twisted together. The cords 16 are enveloped with a rubbermixture which was selected in accordance with the desiredcharacteristics of the rubberized ply. The rubberized ply 15 howevernormally contains only cords 16 of two threads 17 or only cords 16 ofthree threads 17. FIG. 36 thus only serves to illustrate variouspossibilities.

The cords 16 of the rubberized ply 15 can for example consist of twoaramid threads which are twisted together and the titer of which amountsto 1670 dtex. The cord density in the rubberized layer 15 can preferablyamount to between 70 and 120 cords per 10 centimeters.

The strips for the strip bandage 13 can be cut off from the marginalregions of the rubberized layer 15. The remaining part of the rubberizedlayer 15 is then used for the cut breaker plies of the breakerarrangement 4, with the remaining part of the rubberized ply 15 beingcut for this purpose into individual cut breaker plies at an angle whichcorresponds to the desired cord angle of the respective cut breaker plyrelative to the mid-circumferential plane 14.

A further possible layout of the cover ply 5 is shown in FIG. 37. Herethe cover ply 5 is formed in each of the two shoulder regions 18 by arespective helically wound strip bandage 19 and 20 respectively, and inthe central tire region 21 lying between them by a broad band 22. Thetwo strip bandages 19 and 20 preferably have threads or cords of aramid,while the broad band 22 is provided with threads or cords of rayon.

The individual windings of the strip bandage 19 and 20 can also bearranged abutting one another or overlapping one another, other than inthe schematic illustration of FIG. 37. In just the same way, the twostrip bandages 19 and 20 can be respectively arranged abutting the broadband 22 or can overlap the latter, with the strip bandages 19 and 20 orthe broad band 22 being arranged radially outwardly as desired.

In the variant illustrated in FIG. 38, a strip bandage 23 is alsoprovided as the cover ply 5 in the central region 21 of the tire, inaddition to the two strip bandages 19 and 20 in the two shoulder regions18 of the tire. With this layout, the individual turns of the stripbandages 19 and 20 can be wound abutting or overlapping one another in amanner different from that illustrated. In just the same way, theindividual turns of the strip bandage 23 present in the central regionof the region 21 of the tire can be arranged abutting or overlapping oneanother in a different manner from that illustrated.

The turns of the strip bandage 19 or 20 adjacent to the strip bandage 23can respectively overlap the adjacent turns of the strip bandage 23 orcan be overlapped by the latter or be wound abutting the latter. It is,however, also possible to place the start of the strip bandage 23directly at the confronting end of the strip bandage 19 and to place thestart of the strip bandage 20 directly at the end of the strip bandage23. In this manner, a particularly uniform cover ply 5 arises. Thethreads or cords of the strip bandages 19 and 20 also preferably consistof aramid in this variant, whereas the threads or cords of the stripbandage 23 are again preferably formed of rayon. A breaker arrangement 4has in both variants preferably threads or cords of aramid. In this way,a particularly light and strong breaker arrangement is achieved.

The cover ply 5 is preferably so designed that under the condition whichexists during tire manufacture, in particular with the usual pressureduring shaping of approximately 20 bar, a maximum extension of about 0.1to 0.5% in particular 0.3% is possible in the two shoulder regions 18 ofthe tire, whereas in the central tire region 21 a possible extension isset in the range from 2 to 3%, in particular 2.5 to 2.7%. Through thischoice, it is possible to ensure the extension required for the shapinginto the tire mold of the tire blank built up on the cylindricalbuilding drum in the middle tire region 21, whereas in the shoulderregions 18, where practically no extension is necessary, a particularlyfirm covering over of the breaker arrangement 4 is achieved. In themid-region 21 of the tire, this choice moreover counteracts furtherextension so that in the finished tire a good strength of the breakerarrangement 4 is also given in the central region 21 of the tire.

The regions of the cover ply 5 with aramid threads or cords can in allembodiments cover over the breaker arrangement 4 from approximately 10%up to approximately 35 to 40%. The central region of the tireaccordingly extends over about 60 to 90% of the breaker arrangement 4.

The invention therefore allows a light tire to be manufactured in aninexpensive manner which fulfills all the requirements for a moderntire.

Further variations of the construction of the cover ply 5, of thearrangement of the cover ply 5 on the breaker ply 4 as well as of thematerials used are, of course, possible within the scope of theinvention. What always matters is to adjust the stress-strain(force-extension) curve of the cover ply 5 by varying the parametersindicated so that the desired extension behavior of the tire isachieved, i.e. one which, on the one hand, allows the tire to bemanufactured in a satisfactory manner with a clean formation of the tireprofile and, on the other hand, results in optimum tire properties.

Having now described our invention what we claim is:
 1. A pneumaticvehicle tire comprising:a single ply, or multi-ply radial carcassanchored to beads, a tread, a breaker arrangement provided between thecarcass and the tread, the breaker arrangement being built up of atleast two cut breaker plies with the threads or cords of the cut breakerplies, which serve as strength carriers and extend parallel to oneanother in the respective ply, crossing at a predetermined angle to thecentral mid-circumferential plane of the tire, and at least one coverply of threads or cords extending substantially in the circumferentialdirection of the tire, the at least one cover ply surrounding thebreaker arrangement in the two shoulder regions (18) of the tireincluding the breaker arrangement's edge regions and in the centralregion (21) of the tire axially between the shoulder regions, whereinthe threads or cords (9) in the breaker arrangement (4) are ofnon-metallic material; a material with a low thermal shrinkage or nothermal shrinkage is used as the material for the threads or cords (8)of the at least one cover ply (5); and extension of the tire into itstire mold during the tire's manufacture is ensured through the choice ofthe material of the threads or cords (8) of the at least one cover ply(5) alone, or in conjunction with at least one of the group consistingof the nature of the construction of the at least one cover ply (5), theapplication of the at least one cover ply (5), and the nature of theconstruction of the threads or cords (8) of the at least one cover ply(5), but additional extension of the tire is prevented, andwherein theat least one cover ply (5) has, in the two shoulder regions (18) of thetire, an extensibility of at most about 0.1 to 0.5% and, in the centralregion (21) of the tire, an extensibility in the range of from 2 to 3%.2. The pneumatic vehicle tire in accordance with claim 1, wherein thematerial with a low thermal shrinkage or no thermal shrinkage used asthe material for the threads or cords (8) of the at least one cover ply(5) is a material with the largest possible initial modulus ofelasticity and only just permits the extension of the tire into its tiremold during the tire's manufacture.
 3. The pneumatic vehicle tire inaccordance with claim 1, wherein the threads or cords (8) of the atleast one cover ply (5) include threads or cords (8) of rayon.
 4. Thepneumatic vehicle tire in accordance with claim 1, wherein the threadsor cords (8) of the at least one cover ply (5) include threads or cords(8) of a polyester with a high modulus of elasticity and low thermalshrinkage (HMLS polyester).
 5. The pneumatic vehicle tire in accordancewith claim 1, wherein the threads or cords (8) of the at least one coverply (5) include threads or cords (8) of aramid or of a hybrid materialwith aramid.
 6. The pneumatic vehicle tire in accordance with claim 1,wherein the winding density and/or winding tension of the threads orcords of the at least one cover ply are different over the width of thetire with the winding density and/or winding tension being greater inthe breaker arrangement's edge regions.
 7. The pneumatic vehicle tire inaccordance with claim 1, wherein the at least one cover ply (5) isformed as a broad band.
 8. The pneumatic vehicle tire in accordance withclaim 7, wherein the at least one cover ply (5) is formed by simplefolding forming a double ply.
 9. The pneumatic vehicle tire inaccordance with claim 1, wherein the at least one cover ply (5)surrounds the breaker arrangement (4) over its entire width.
 10. Thepneumatic vehicle tire in accordance with claim 9, wherein the threadsor cords (8) of the at least one cover ply (5) in the two shoulderregions (18) of the tire consist of a material which is essentiallynon-extensible and consist in the central tire region (21) disposedbetween the two shoulder regions (18) of a material which permits anextension of the tire by a predetermined amount under the conditionswhich are present during the tire's manufacture but which substantiallyprevents an additional extension of the tire.
 11. The pneumatic vehicletire in accordance with claim 10, wherein the threads or cords (8) ofthe at least one cover ply (5) consist of aramid in the shoulder regions(18) and of rayon in the central region (21) of the tire.
 12. Thepneumatic vehicle tire in accordance with claim 10, wherein the at leastone cover ply (5) in the shoulder regions (18) is formed as a helicallywound strip bandage (19,20).
 13. The pneumatic vehicle tire inaccordance with claim 10, wherein the at least one cover ply (5) in thecentral tire region (21) is formed as a helically wound strip bandage(23).
 14. The pneumatic vehicle tire in accordance with claim 10,wherein the at least one cover ply (5) in the central tire region (21)is formed as a broad band (22).
 15. The pneumatic vehicle tire inaccordance with claim 10, wherein the sections of the at least one coverply (5) in the two shoulder regions (18) of the tire are arrangedabutting the section of the at least one cover ply (5) in the centralregion (21) of the tire.
 16. The pneumatic vehicle tire in accordancewith claim 10, wherein the sections of the at least one cover ply (5) inthe two shoulder regions (18) are arranged overlapping the section ofthe at least one cover ply (5) in the central tire region (21).
 17. Thepneumatic vehicle tire in accordance with claim 1, wherein the threadsor cords (9) in the breaker arrangement (4) are of glass fiber.
 18. Thepneumatic vehicle in accordance with claim 1, wherein the threads orcords (9) in the breaker arrangement (4) are of carbon fiber.
 19. Thepneumatic vehicle tire in accordance with claim 1, wherein the threadsor cords (9) in the breaker arrangement (4) and the threads or cords (8)of the at least one cover ply (5) are threads or cords (16) of the samematerials and with the same titer.
 20. The pneumatic vehicle tire inaccordance with claim 19, wherein the thread or cord density is the samein the individual breaker plies of the breaker arrangement (4) and inthe at least one cover ply (5).
 21. The pneumatic vehicle tire inaccordance with claim 19, wherein the breaker arrangement (4) is builtup of two breaker plies of aramid threads or cords and the at least onecover ply (5) is formed as a helically wound strip bandage (13) ofaramid threads or cords.
 22. The pneumatic vehicle tire in accordancewith claim 21, wherein the threads or cords of the breaker ply and atleast one cover ply are cords (16) of two intertwined aramid threads(17), each having a titer of 1670 dtex, the cord densities in theindividual breaker plies of the breaker arrangement (4) amount toapproximately 70 to 120 cords per 10 cm, and in the at least one coverply (5) the cord density amounts to approximately 60 to 90 cords per 10cm.
 23. The pneumatic vehicle tire in accordance with claim 1, whereinthe at least one cover ply (5) is formed as a helically wound stripbandage (13).
 24. The pneumatic vehicle tire in accordance with claim23, wherein at least some of the adjacent windings of the strip bandage(13) overlap.
 25. The pneumatic vehicle tire in accordance with claim24, wherein the width of overlap differs over the width of the tire. 26.The pneumatic vehicle tire in accordance with claim 25, wherein overlapof the strip bandage (13) is only present in the regions of the at leastone cover ply (5) which cover over the breaker arrangement's edgeregions.
 27. The pneumatic tire in accordance with claim 23, wherein thesense of winding of the strip bandage (13) is different over the widthof the tire.
 28. The pneumatic vehicle tire in accordance with claim 27,wherein the sense of winding on one side of the mid-circumferentialplane (14) is opposed to the sense of winding on the other side of themid-circumferential plane (14).
 29. The pneumatic vehicle tire inaccordance with claim 23, wherein the winding direction of the stripbandage (13) is different over the width of the tire.
 30. The pneumatictire in accordance with claim 29, wherein the winding direction on oneside of the mid-circumferential plane (14) is opposed to the windingdirection on the other side of the mid-circumferential plane (14). 31.The pneumatic vehicle tire in accordance with claim 1, wherein thethreads or cords (9) in the breaker arrangement (4) are of textilematerial.
 32. The pneumatic vehicle tire in accordance with claim 31,wherein the threads or cords (9) in the breaker arrangement (4) are ofrayon.
 33. The pneumatic vehicle tire in accordance with claim 31,wherein the threads or cords (9) in the breaker arrangement (4) are ofHMLS polyester.
 34. The pneumatic vehicle tire in accordance with claim31, wherein the threads or cords (9) in the breaker arrangement (4) areof aramid.
 35. A method of manufacturing a tire comprising the stepsof:assembling a plurality of tire components into a tire blank, saidtire blank comprisinga single ply or multi-ply radial carcass anchoredto beads, a tread, a breaker arrangement provided between the carcassand the tread, the breaker arrangement being built up of at least twocut breaker plies with the threads or cords of the cut breaker plies,which serve as strength carriers and extend parallel to one another inthe respective ply, crossing at a predetermined angle to the centralmid-circumferential plane of the tire, the threads or cords (9) in thebreaker arrangement (4) being of a non-metallic material, and at leastone cover ply of threads or cords extending substantially in thecircumferential direction of the tire, the at least one cover plysurrounding the breaker arrangement in the two shoulder regions (18) ofthe tire including the breaker arrangement's edge regions and in thecentral region (21) of the tire axially between the shoulder regions,the threads or cords (8) of the at least one cover ply (5) being of amaterial of low thermal shrinkage or no thermal shrinkage; and moldingthe tire blank in a tire mold, whereinthe step of assembling includes astep of ensuring extension of the tire into the mold, but preventingadditional extension of the tire through the choice of the material ofthe threads or cords (8) of the at least one cover ply (5) alone, or inconjunction with at least one of the group consisting of the nature ofthe construction of the at least one cover ply (5), the application ofthe at least one cover ply (5), the nature of the construction of thethreads or cords (8) of the at least one cover ply (5), and the natureof the build-up of the breaker arrangement (4), such that the at leastone cover ply (5) has, in the two shoulder regions (18) of the tire, anextensibility of at most about 0.1 to 0.5% and, in the central region(21) of the tire, an extensibility in the range of from 2 to 3%.
 36. Themethod in accordance with claim 35, wherein the step of ensuringincludes choosing the nature of the construction of the threads or cords(8) of the at least one cover ply (5) so that the threads or cords (8)of the at least one cover ply (5) are as thin as possible and as thickas necessary and/or the threads or cords (8) of the at least one coverply (5) are twisted to a predetermined degree.
 37. The method inaccordance with claim 35, wherein the step of ensuring includes choosingthe nature of the construction of the at least one cover ply (5) bychoosing at least one of the group consisting of the geometricalarrangement of the at least one cover ply (5), the thread or corddensity in the at least one cover ply (5) and the winding density and orwinding tension of the at least one cover ply (5).
 38. The method inaccordance with claim 35, wherein the step of ensuring includes choosingthe nature of the built-up of the breaker arrangement (4) by choosingthe nature of the type and/or construction of the threads or cords (9)of the breaker arrangement (4).